I would guess that if the car is bouncing the shock is too loose? If I tighten up the shocks on my car too much it will blow the tires off. If I set them too loose the weight transfer overcomes the shocks and the car will do strange things (not want to go straight, feel spongy, etc.) This is a four speed car and I don't know that much about this stuff so take it with a grain of salt.

Perhaps the shock was too stiff and causing the car to bounce on the tire? What does the vid show?